Portion of a bag



FIG. 1 is a front view of a a portion of a bag showing our new design illustrating a detail area;

FIG. 2 is a perspective view thereof; and,

FIG. 3 is a side view thereof.

The broken line showing of the remainder of the bag in FIGS. 1-3 is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a portion of a bag, as shown and described. 